In the aforementioned patent application Ser. No. 575,146 now U.S. Pat. No. 4,011,801 and my previous U.S. Pat. Nos. 3,482,506 and 3,877,536, I have disclosed various air projection grilles for use at cooled air, heated-air or ventilating-air outlets to diffuse the emerging supply air and induce ambient air into the emerging supply air so as to form a coherent blanket of air which accomplishes this mixing in the ceiling zone and minimizes drafts or air turbulence in the occupied zone.
My U.S. patent application Ser. No. 575,146 now U.S. Pat. No. 4,011,801 shows an air diffuser which embodies one or more novel unitary wedge strips mounted at an air outlet to produce the desired coherent blanket (or blankets) of air.
The present invention is directed to a universal type diffuser for attachment below a ceiling air outlet in a room. Its purpose is to cover, but not necessarily fit, the outlet which may vary in size, shape and structural design. It can function equally well with round or rectangular shaped outlets, regardless of their location in the ceiling. More specifically the outlets may be conventional grilles, diffusers or even open air ducts. Some of these outlet devices attempt to turbulate the supply air to stimulate temperature blending with the ambient air, but the most popular types are virtually nothing more than pouring devices operating in 1, 2, 3 or 4 directions. They operate on the principle of projecting cold (heavy) supply air into the ambient room air to accomplish mixing. The result is uncomfortable and unhealthy cold drafts, cold floors and non-uniform temperature distribution in the occupied (living) zone.
The present invention operates on an entirely different principle by converting turbulent supply air from the outlet to a coherent blanket-like formation that is highly inductive and can be spread over an entire room. Because of these qualities, this relatively thin blanket of coaductive air flow not only tends to follow the ceiling but also draws ambient room air up to itself, thus accomplishing rapid and complete mixing in the ceiling zone away from room occupants. This eliminates uncomfortable drafts or air turbulence in the occupied zone and promotes the best possible uniformity of air and temperature throughout the entire room.
The present invention greatly alleviates the problem of air "starvation" at the corners and produces a continuous relatively thin, radial blanket of substantially uniform coaductive air flow from a rectangular shaped arrangement of wedge strips. This improvement is accomplished through manipulation of the structural (elastic) strength of the cohesive blanket by weakening the straightforward portion produced by the middle of the wedge strip and increasing the strength of the corner portions produced by the wedges nearer the ends of the strip. My understanding is that the cohesive blanket formed by a single wedge strip is stretched through 90.degree. (45.degree. on each side of straight forward) and that the stronger portions tend to become stronger (thicker) and the weaker portions tend to become weaker (thinner). The natural tendency is for the center portion to be the strongest, hence the need for equalization by shifting more strength toward the ends.
In contrast to the present invention the most widely used conventional rectangular grilles distribute little or no air from the corners. Those that are 1, 2, 3 or 4-way types usually have uni-directional projection from a side. For example, the 1-way would project in only one direction, and the 4-way would leave large distribution "voids" at each corner.
The present invention when applied as a cover over a conventional grille or diffuser not only converts the supply air to coaductive flow but also distributes some air in all directions. When applied to a 1-way type grille most of the air will travel in a spreading forward direction with lesser amounts at the sides and very little at the rear. On a 4-way type the distribution would become continuously radial and substantially uniform throughout 360.degree.. If it is desired to block out an entire side or portion of a side, this can be done, as explained hereinafter.